Recipe

Judging by name alone, “supercharged spirits” sounds like a Four Loko experiment gone terribly wrong (or very right, depending on your night out). But for Mixologist Michael Callahan of Singapore’s 28 HongKong Street, supercharged simply means doubling down on flavor—achieved by packing two bottles of liquor into one.

Drawing inspiration from Camper English’s Solid Liquid Project, Callahan, who left San Francisco for Singapore in 2011, dehydrates whole bottles of Aperol, reducing the liquor to a mound of flavored, crystallized sugar. He then pulverizes the crystals in a mortar and pestle and reincorporates them into a fresh bottle of Aperol—essentially supercharging the flavor. “It doubles the flavor compounds but keeps the ABV the same,” says Callahan.

Using a dehydrator (Callahan swears by his “bulletproof” Ezidri FD1000) set to 55°C to 60°C (below the boiling point for alcohol, 78°C), it takes four to five days to go from liquid orange liquor to a pile of Aperol-flavored sugar. Callahan also dehydrates Chartreuse, Campari, and Fernet and uses the crystals for simple syrups and sprinkles. Almost any high-sugar spirit works, he says, as long as it isn’t loaded with impurities and chemical additives. “You need a clean spirit. If there are lots of impurities, it will inhibit crystallization of the sugar and never fully dehydrate.”

For supercharging, Callahan dissolves the Aperol crystals into liquid Aperol with a magnetic stirrer, cold processing the mixture to prevent the negative effects of heat. If you don’t happen to have a high-tech magnetic stirrer (the device uses a spinning magnet to create a rapidly swirling vortex that efficiently disperses the solid crystals), Callahan recommends vigorously agitating the mixture to combine.

Rosita

Callahan uses the amped Aperol in his Rosita variation, traditionally made with tequila, Campari, sweet vermouth, dry vermouth, and Angostura bitters. For his version, he adds ¼ ounce Sombra mezcal and subs in supercharged Aperol for Campari. “[Supercharging] gave the Aperol an extra kick of citrus and bitterness, but not as much as Campari,” he says. “It gave me the in between flavor I was looking for.”

The drink also lends itself well to batching, which Callahan employs to keep ticket times down to nine minutes. For the Rosita, he mixes all the ingredients pre-service—save the supercharged Aperol. “When you batch, you lose the magic of being a bartender,” says Callahan. As it turns out, pouring Aperol with “Supercharged” scrawled across the label is quite a conversation starter. “Keeping the supercharged Aperol out of the batch give us the chance to talk.” And explain, at least in part, the cocktail’s $21 price tag (about $17 U.S. dollars and on par with the average cocktail price in Singapore).

Although Callahan and his team are working to improve distribution channels, sourcing spirits in Singapore is an expensive and arduous proposition. (Much of Callahan’s back bar was built by friends who bought spirits retail in the States, lugged them to Singapore, and paid import duties.) Even relatively common spirits like Campari, Fernet, and Aperol sometimes just aren’t available. In that climate, dehydrating a whole bottle of Aperol is practically sacrilegious, but experiencing Callahan’s Rosita proves that sometimes a bartender has to sacrifice alcohol (and a smidge of profit) in the name of supercharged flavor.

Supercharged Aperol Technique

Pour one bottle Aperol into a wide, shallow vessel.

Place in dehydrator set to 55°C to 60°C; dehydrate four to five days, checking twice daily and agitating to make sure Aperol is drying evenly.

Once all liquid has evaporated, crush the dehydrated Aperol crystals in a mortar and pestle.

Pour liquid Aperol into a wide glass beaker set atop a plate stirrer.

By volume, add 1:10 ratio Aperol crystals to liquid Aperol.

Stir with a magnetic spoon until crystals dissolve.

Pour supercharged liquid back into a bottle and seal (attaching “Supercharged” label for full effect).